KR100694903B1 - Waste gas treating device - Google Patents

Abstract

In the waste gas processing apparatus which has a burner part and the combustion chamber downstream of this burner part, forms a combustion flame from a burner part toward a combustion chamber, introduce | transduces waste gas into this combustion flame, and oxidizes this waste gas. Since the combustion chamber is formed by the inner wall of the fiber reinforced ceramic material, the wear of the inner wall and the corrosion resistance is minimized, and the thermal stress crack is also reduced.

Thus, the service life of the system can be increased, and the installation cost and operation rate can be improved. In addition, since the inner wall does not catalyze, formation of NOx by heat can be suppressed, the environment can be preserved, and the apparatus can be simplified.

Description

Waste Gas Treatment System {WASTE GAS TREATING DEVICE}

The present invention relates to a waste gas treating apparatus that is likely to generate dust when burned. For example, combustion flammable or hardly decomposable waste gas containing silane gas (SiH ₄ ) or halogen-based gas (NF ₃ , ClF ₃ , SF ₆ , CHF ₃ , C ₂ F ₆ , CF _4, etc.). The present invention relates to a combustion type waste gas treatment apparatus for treatment.

The waste gas which tends to generate dust when burned is toxic combustible gas such as silane (SiH ₄ ) or disilane (Si ₂ H ₆ ) from a semiconductor manufacturing apparatus or a liquid crystal panel manufacturing apparatus. In addition, there are gases containing hardly degradable global warming gases (PFCs), but these waste gases cannot be released into the atmosphere because they adversely affect the human body or change the global environment. Therefore, a pretreatment system is introduced to make the waste gas harmless by oxidation while burning the waste gas. As a treatment method, an auxiliary combustion gas is used to form a flame in the furnace, and the waste gas is burned in the flame.

In such a combustion waste gas treatment system, the auxiliary combustion gas uses hydrogen, city gas, LPG, or the like as a fuel gas, and oxygen or air is usually used as the oxidant, and the operating cost of this apparatus is their combustion gas or oxidant. Most of the cost is spent. Therefore, how many harmful waste gases are decomposed under high efficiency by using less auxiliary combustion gas is one of the measures for evaluating the performance of this kind of device.

27 and 28 show a general configuration of a combustor used in the conventional combustion type waste gas treatment apparatus. It is provided with the burner part 101 and the combustion reaction part (combustion chamber) 102 which heat-oxidizes waste gas at the next stage of the burner part 101. The burner unit 101 includes a waste gas nozzle 103 opened in the center of the ceiling of the combustion reaction unit 102 to introduce waste gas G1 to be treated in the combustion reaction unit 102. This waste gas nozzle 103 has a plurality of auxiliary combustion gas nozzles 104. The auxiliary combustion gas nozzle 104 is opened to the outer circumference of the waste gas nozzle 103 to introduce the auxiliary combustion gas G2 into the combustion reaction unit 102. Combustion gas outlet 105 is connected to the lower end of the combustion reaction unit 102 as a whole. As a result, the waste gas passes through the central portion of the flame formed in a ring shape by the auxiliary combustion gas G2 ejected from the auxiliary combustion gas nozzle 104. While passing through the center of the flame, the waste gas G1 is mixed with the flame and combusted. The combustion gas by combustion of the waste gas G1 is discharged | emitted from the combustion gas outlet 105 to the exterior.

Generally, the combustion reaction part 102 is generally formed in the inner wall surface 106a of the cylindrical furnace body 106 made of metal, such as stainless steel, and is made into the outer peripheral surface of this furnace 106 as needed. The structure which provides a single heat insulating material or water-cooled was employ | adopted.

On the other hand, as a method of decomposing a gas such as a fluorocarbon system which is currently a cause of global warming, thermal decomposition in a high temperature environment or decomposition in plasma is mainly used. In order to use these methods, in a decomposition treatment facility equipped with a complicated control mechanism for controlling a heating device such as a heater, a plasma generating device, and a safety device, a large amount of energy is imparted to generate a heating plasma to contain fluorocarbons. The gas is decomposed.

However, in the conventional example as shown in FIG. 27 and FIG. 28, since the combustion reaction part 102 is comprised from the metal furnace body 106, and is exposed to the high temperature atmosphere of 1300 degreeC or more at the time of combustion flame formation (operation). The exhaust body 106 was consumed so much that it could not withstand a long time of operation. In particular, when the gas containing halogen is decomposed in this apparatus, the furnace body is etched or corroded under high temperature by the halogen gas (HCl, HF, etc.) generated after the treatment reaction, and is consumed severely.

In this manner, when the furnace body 106 is consumed in a short time, it is necessary to replace it frequently, resulting in high equipment cost. In addition, when the metal body is consumed, there is a risk that the structure will be consumed to the surrounding structure (insulation material, water cooling container, etc.). Therefore, it is necessary to disassemble and check the degree of consumption of the body frequently. Causes an increase.

In addition, since the inner wall surface of the metal furnace body 106 is heated to a high temperature by the combustion flame in the combustion reaction section 102, the generation of thermal NOx is encouraged by the catalytic effect of the metal. For example, this kind of waste gas combustion facility in a semiconductor industrial facility is generally designed to be installed in a clean room, and it is necessary to reduce the size of the facility, but if a large amount of NOx is generated, it is treated. There is a need to separately provide a dedicated treatment mechanism, and as a result, it cannot be miniaturized.

In addition, in the combustor forming the combustion flame as described above, the flame is formed at the lower end of the burner portion 101, and as a result, the temperature in the vicinity of the opening of the burner portion 101 made of stainless steel or the like rises to increase the burner portion 101. There was a risk of explosion of the auxiliary combustion gas (G2) supplied to the flash.

In addition, there is a gas that generates dust such as SiO ₂ when it is made harmless in a pyrolysis type waste gas treatment apparatus such as SiH ₄ used in the manufacturing process of semiconductor devices, particularly in the CVD process. Such dust flows along with the waste gas and adheres to inner wall surfaces of pipes and the like, thereby increasing the exhaust pressure loss. As a method of preventing the dust from adhering to the inner wall surface of the pipe, the conventional method of blowing by clean gas, the scraping method by the intermittent manual scraping device, and the clean gas always being supplied through the porous inner wall to prevent the adhesion of dust There was a way.

The blow off method by clean gas is a method of installing a fixed nozzle in the entire circumferential direction of a pipe and blowing out clean gas at all times or intermittently to remove dust. This method has a problem that the dust removal effect is lowered when the nozzle is far from the dust attachment position, and not only does the cost of the clean gas itself for flowing a large amount of clean gas so that the effect does not decrease. There was a problem that the pipe had to be thickened in order to reduce the pressure loss due to the flow of gas.

Since the scraping method by the intermittent manual scraping apparatus is largely grown with dust, scraping is performed. Therefore, a tank for storing a large amount of scraped dust is required.

Also, to prevent dust from adhering by always supplying clean gas through the porous inner wall, a large amount of clean gas must be supplied to maintain the flow rate of the clean gas from the inner wall throughout the pipe to prevent the dust from adhering. In order to reduce pressure loss due to gas flow, there is a problem that the pipe is not made thick unless it is thickened.

In addition, there is a problem in that the cost of clean gas itself or a facility such as a duct for exhausting the gas discharged from the pretreatment device from the inside of the building to the outside of the building must be increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to suppress the consumption of the inner wall constituting the combustion reaction section exposed to high temperature to improve the service life, to improve the equipment cost and operation efficiency, and to suppress the generation of NOx. It is an object to provide a waste gas treatment apparatus.

In addition, an object of the present invention is to provide a waste gas treatment apparatus that suppresses an increase in temperature caused by a flame near an opening of a combustion burner and does not cause an explosion of auxiliary combustion gas.

In addition, an object of the present invention is to provide a waste gas treatment apparatus which can reliably remove dust adhering to the inner wall surface of a pipe and in which a clean gas amount is minimal even when spraying clean gas.

The present invention provides a waste gas treatment apparatus having a burner portion and a combustion chamber provided downstream of the burner portion, forming a combustion flame from the burner portion toward the combustion chamber, and introducing waste gas into the combustion flame to oxidatively decompose the waste gas. In this case, the combustion chamber is formed of an inner wall made of a fiber-reinforced ceramic material, thereby minimizing the consumption of heat and corrosion of the inner wall, and reducing the occurrence of cracking due to thermal stress, thereby improving the life of the device and improving the equipment cost and operation rate. At the same time, since the inner wall does not exhibit a catalytic effect, it is possible to suppress the generation of thermal NOx and to maintain the environment and simplify the treatment equipment. In addition, since the space between the inner wall and the outer container is maintained in a purge gas atmosphere having a pressure higher than that of the combustion chamber, it is possible to prevent leakage of harmful gases in the combustion chamber to the outside.

In the waste gas treatment apparatus, the burner portion is provided with a cylindrical member having a vertex closed and having an opening at the bottom thereof, and providing a waste gas inlet at the vertex of the cylindrical member, and at a predetermined position on the side wall. An air nozzle is installed, and an auxiliary combustion gas nozzle is installed on the side wall near the opening to mix waste gas introduced from the waste gas inlet and air ejected from the air nozzle, and to the auxiliary combustion gas ejected from the auxiliary combustion gas nozzle. It is configured to ignite to form a combustion flame toward the lower side of the opening, and by providing cooling means for cooling the auxiliary combustion gas inlet for introducing fuel gas to the auxiliary combustion gas nozzle, the auxiliary combustion gas introduction portion is heated even by the flame to assist the temperature rise. Since the combustion gas is kept below the ignition point, there is no danger of the secondary combustion gas or the like exploding.

In addition, in the waste gas treatment apparatus, dust removal means for removing the dust attached to the burner part and / or the inner wall of the combustion chamber or preventing the dust from adhering to the waste gas treatment apparatus is provided to enable long time operation of the waste gas treatment apparatus.

In addition, a dust remover is provided to remove dust attached to the inner wall of the pipe through which gas containing a lot of dust flows. The dust remover includes a scraping mechanism installed in the piping. The scraping mechanism is configured to have a rod-shaped scraping member disposed in the pipe and extending in the longitudinal direction of the pipe to the main shaft. The dust remover is a support mechanism for supporting the main shaft of the scraping mechanism so that the scraping member can contact the inner surface of the pipe or move in the inner circumferential direction at a slight distance, and the scraping mechanism can be continuously or periodically oscillated about the main shaft. Or a driving device for rotating. Therefore, clean air is supplied from the outside of the pipe through the hollow of the main shaft and the scraping member, and clean air is blown out from the tip of the scraping member or a plurality of holes or slits on the surface thereof. As a result, not only the dust in the pipe which the scraping member does not touch can be removed, but also the dust attached to the scraping mechanism itself can be removed.

Further, the waste gas treatment apparatus includes a burner portion having a cylindrical member having a top portion closed and an opening portion at a lower portion thereof. The cylindrical member has a waste gas inlet at its apex and an air nozzle at a predetermined position on the side wall. The cylindrical member further includes an auxiliary combustion gas nozzle on the side wall near the opening. The air nozzle is arranged to promote the ignition of the auxiliary combustion gas injected from the auxiliary combustion gas nozzle and to blow down the swirling air flow downward in the combustion flame formed toward the bottom of the opening. Therefore, it is difficult for dust to adhere to the inner wall of the burner part.
In addition, the burner part of the exhaust gas treating apparatus is provided with a cylindrical member having a top part closed and an opening part at a lower part thereof. An exhaust gas introduction port is provided at the top of the cylindrical member, and an air nozzle is provided at a predetermined position of the side wall. The cylindrical member further includes an auxiliary combustion gas nozzle on the side wall near the opening. The inner diameters of the waste gas inlet and the cylindrical member gradually increase toward the combustion chamber. As a result, there is no angled portion such as a right angle portion in the burner portion, and dust is hard to adhere to the inner wall of the nozzle portion.
The burner section of the waste gas treatment apparatus has a combustion chamber downstream of the burner section and a combustion gas cooling section downstream of the combustion chamber. The burner part, the combustion part, and the combustion gas cooling part are provided integrally. The burner part is provided with a waste gas inlet for introducing waste gas and an air nozzle for injecting air to generate swirl flow. The combustion gas cooling unit includes a liquid spray nozzle for cooling the exhaust gas flowing from the combustion chamber and spraying liquid for capturing dust in the exhaust gas, an exhaust pipe for discharging the exhaust gas, and a liquid sprayed from the liquid spray nozzle. A drainage pipe for draining is provided. By constructing the waste gas treatment device in this way, it is possible to efficiently capture and absorb the waste gas, and the dust, HCl and HF in the waste gas introduced from the waste gas inlet to the liquid sprayed from the spray nozzle.

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1 is a view showing the configuration of a waste gas burner of the waste gas treating apparatus according to the present invention;

2 is a cross-sectional view taken along the line I-I of FIG.

3 is a view showing an example of the configuration of a burner section of the waste gas treating apparatus according to the present invention;

4 is a view seen from the direction of arrow A of FIG.

5 is a view showing an example of the configuration of a burner section of the waste gas treatment apparatus according to the present invention;

6 is a view seen from the direction of the arrow (D) of FIG.

7 is a view showing an example of the configuration of a burner section of the waste gas treating apparatus according to the present invention;

8 is a view seen from the direction of the arrow E of FIG.

9 is a view showing an example of the configuration of a burner section of the waste gas treating apparatus according to the present invention;

FIG. 10 is a view seen from the arrow F in FIG. 9,

11 is a view showing a configuration example of a burner section of the waste gas treatment apparatus according to the present invention;

12 is an external view of the cooling jacket of FIG.

13 is a view showing a configuration example of a dust removing apparatus of the waste gas treating apparatus according to the present invention;

14 is a plan view of the scraping plate of FIG.

15 is a surface showing an example of the configuration of a dust removing apparatus of the waste gas treating apparatus according to the present invention;

FIG. 16 is a cross-sectional view taken from the arrow direction II-II in FIG. 15;

17 is a surface showing an example of the configuration of a dust removing apparatus of the waste gas treating apparatus according to the present invention;

FIG. 18 is a cross-sectional view taken from the direction of arrow Ш- Ш in FIG. 17;

19 is a view showing a configuration example of a dust removing apparatus in a pipe according to the present invention;

20 is a view showing a configuration example of a dust removing apparatus in the waste gas treating apparatus according to the present invention;

21 is a view showing a configuration example of a dust removing apparatus in a pipe according to the present invention;

22 is a diagram showing an example of the configuration of a dust removing apparatus in a pipe according to the present invention;

23 is a diagram showing an example of the configuration of a dust removing apparatus in a pipe according to the present invention;

24 is a diagram showing an example of the configuration of a burner section of the waste gas treating apparatus according to the present invention;

FIG. 25 is a view seen from the direction of arrow L in FIG. 24;

Fig. 26 is a diagram showing an example of the configuration of a burner section of the waste gas treating apparatus according to the present invention;

27 is a view showing a configuration example of a conventional waste gas treatment system;

FIG. 28 is a sectional view seen from IV-IV direction in FIG. 27; FIG.

1 and 2 are views showing the configuration of a waste gas burner of the waste gas treatment apparatus according to the present invention, FIG. 1 is a longitudinal sectional view, and FIG. This waste gas burner is constituted as a cylindrical sealed container as a whole, and is composed of a burner part 10 at the upper end and a combustion chamber (combustion reaction part) 30 at the upper end, and a cooling part 51 and a discharge part 52 at the lower end. ). As the cooling medium of the cooling unit 51, for example, a liquid such as water or a gas such as air is used.

The burner part 10 includes a cylindrical member 11 that forms a flame holding part 18 that opens toward the combustion chamber 30, and an outer cylinder 12 that surrounds the cylindrical member 11 at a predetermined interval. An air chamber 19 for holding combustion air between the cylindrical member 11 and the outer cylinder 12 and an auxiliary combustion gas chamber for holding auxiliary combustion gas of, for example, a premixed gas of hydrogen and oxygen ( 20) is formed. These air chambers 19 and the auxiliary combustion gas chambers 20 are in communication with a source of air and a gas source, respectively (not shown). Here, hydrogen, propane, city gas and the like are used for the auxiliary combustion gas.

At the top of the cylindrical member 11 covering the flame holding unit 18, waste gas G1 containing silane (SiH ₄ ), etc. discharged from a semiconductor manufacturing apparatus, is introduced into the flame holding unit 18. The waste gas introduction pipe 14 is connected.

The cylindrical member 11 includes a plurality of air nozzles 15 communicating with the air chamber 19 and the flame holding unit 18, and a plurality of auxiliary combustion units communicating with the auxiliary combustion gas chamber 20 and the flame holding unit 18. The gas nozzle 16 is provided. As shown in FIG. 2, the air nozzle 15 extends with a predetermined angle with respect to the tangential direction of the cylindrical member 11, and blows air in order to form the swirl flow in the flame holding part 18. As shown in FIG. Similarly, the auxiliary combustion gas nozzle 16 extends at a predetermined angle with respect to the tangential direction of the cylindrical member 11, and blows out the auxiliary combustion gas to form a swirl flow in the flame holding unit 18. The air nozzle 15 and the auxiliary combustion gas nozzle 16 are equally arranged in the circumferential direction of the cylindrical member 11.

A secondary air chamber 31 is formed around the boundary between the flame holding unit 18 and the combustion chamber 30 so as to surround the opening of the flame holding unit 18, and the secondary air chamber supplies secondary air. Is in communication with an air source (not shown). In the partition plate 32 partitioning between the secondary air chamber 31 and the auxiliary combustion chamber 30, a secondary air nozzle 33 for ejecting secondary air for oxidizing waste gas in the combustion chamber 30 is provided. It is arrange | positioned evenly in the circumferential direction.

 The combustion chamber 30 is a space for oxidatively decomposing waste gas in the next stage of the burner unit 10, and is arranged to be continuous with the flame holding unit 18 inside the hermetic cylindrical outer container 34 formed of metal or the like. It is arranged in a cylindrical inner wall 35. This inner wall 35 is formed of fiber reinforced ceramics, as will be described later. In addition, a porous ceramic heat insulating material 37 is inserted into the space 36 between the inner wall 35 and the outer container 34. A purge air inlet pipe 40 for introducing purge air into the space 36 is connected to the outer container 34.

The fiber-reinforced ceramic constituting the inner wall 35 is made by weaving a fiber formed from a ceramic material, applying a ceramic material containing a binder to it, and forming it into a cylindrical shape to solidify it. Overlapping is formed. As such, by reinforcing the ceramic itself with ceramic fibers, mechanical strength and high temperature strength can be improved. As a result, cracks can be reduced even when the inner wall 35 is exposed to high temperature with combustion and thermal stress acts. In addition, etching or corrosion is unlikely even by a corrosive gas such as halogen gas generated by combustion treatment. Therefore, it is possible to obtain a long-term content period. On the other hand, the heat insulating material 37 made of porous ceramics may be formed by forming a fiber from the ceramic material and forming it with a molding suction device so as to conform to the shape of the space 36.

As the heat insulating material 37 and the inner wall 35, ceramic materials include, for example, alumina having a purity of 80 to 99.7%, Si-based ones, and the like. When treating a gas containing fluorine, it is preferable to use alumina having high corrosion resistance to this waste gas. As a fiber-reinforced ceramic material for the inner wall 35, when alumina continuous fiber is used, it is high in heat resistance, wind resistance, and abrasion resistance, and can withstand a large thermal shock and a temperature gradient.

The combustion chamber 30 is provided with a UV sensor 38 for detecting a flame and a pilot burner 39 for igniting the burner section 10. In addition, the UV sensor 38 and the pilot burner 39 may be provided at the top of the cylindrical member 11 (top plate of the burner section 10) as shown in FIG. Since the UV sensor 34 detects the flame formed from the inclined direction, it arrange | positions inclined with respect to the vertex part of the cylindrical member 11. This is because the flame forms swirl flow in the combustion chamber 30, and the flame is shortened in the radial direction. When the silane (SiH ₄ ) is treated, dust of SiO ₂ adheres to the inner wall surface of the combustion chamber 30 so that the UV sensor 38 cannot detect the flame. Thus, the UV sensor 38 is burned in the burner unit 10. By installing on the ceiling plate, the problem that a flame cannot be detected by dust adhesion can be avoided. In addition, since the high temperature of 1300 ° C. or higher is required to treat hardly degradable PFCs, the pipes are corroded by heat, but as described above, the UV sensor 38 and the pilot burner 39 By providing it to the ceiling plate of the burner part 10, corrosion by such a high temperature can be avoided.

The discharge part 52 is provided in the lower part of the combustion chamber 30 with the cooling part 51 which is placed between the combustion chamber 30 and the discharge part 52. In the cooling section 51, a plurality of nozzles 53 are provided in the lower edge portion at equal intervals in the circumferential direction, and water is sprayed from the nozzle 53 toward the center to form a curtain of water to cool the waste gas. It is supposed to capture the particles in the waste gas. The side wall of the discharge part 52 is provided with an exhaust pipe 54 for exhausting the treated waste gas, and a drain port 55 for discharging water injected from the nozzle 53 is provided at the bottom.

Next, operation | movement of the waste gas processing apparatus of the said embodiment is demonstrated. First, the auxiliary combustion gas is introduced into and maintained in the auxiliary combustion gas chamber 20, and turns from the auxiliary combustion gas nozzle 16 provided on the inner circumferential surface of the cylindrical member (inner cylinder) 11 toward the flame holding part 18. It is ejected to produce. When ignited by the pilot burner 39, a swirling flame is formed on the inner circumferential surface of the cylindrical member (inner cylinder) 11.

Here, the auxiliary combustion gas forms a swirling flame, but the swirling flame has a feature capable of stably combusting over a wide range of equivalent ratios. In other words, because it turns strongly, the flame holding characteristics are enhanced by supplying heat and radicals to each other. Therefore, normally, even in small equivalent ratios, such as generating unburned gas or extinguishing a flame, it can be stably combusted without generating unburned gas and causing pulsating combustion even near the equivalent ratio 1.

On the other hand, the waste gas G1 to be treated is ejected toward the flame holding unit 18 from the waste gas introduction pipe 14 opened at the lower surface of the apex of the cylindrical member 11. The ejected waste gas G1 is mixed with the swirling flow of the auxiliary combustion gas and combusted, but at this time, the auxiliary combustion gas is ejected to strongly turn in one direction downstream from all the auxiliary combustion nozzles in the circumferential direction. All of them are mixed well with the flame, and the combustion efficiency of the waste gas becomes very high.

If the auxiliary combustion gas is overheated above its ignition temperature and the oxidant is contained in the auxiliary combustion gas, combustion may start in the auxiliary combustion gas chamber 20. Needs to be. In addition, it has been found by the present inventors that the swirling flame heats the auxiliary combustion gas in the cylindrical member 11 and the auxiliary combustion gas chamber 20. Therefore, in order to continue stable combustion, it is necessary to cool so as not to exceed the heat resistance temperature of the constituent material of the cylindrical member 11. The swirling air flow injected from the nozzle 15 of the air to the flame holding unit 18 serves to cool the auxiliary combustion gas chamber 20.

In addition, the flame from the auxiliary combustion gas nozzle 16 turns and is injected, but since the air injected from the air nozzle 15 is also turning, this air flow mixes with the flame to further accelerate the swirl flow of the flame to make a strong turn. Forms a stream. When the swirling flame is formed, the pressure of the air flow at the center of the swing decreases, and a self-circulating flow flows back from the end of the flame toward the waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 10 at the center, and this circulation flow is assisted. Mixing with the flame and combustion gas from the combustion gas nozzle 16 suppresses generation of NOx. Alternatively, low NOx combustion is possible even if the equivalent ratio of the auxiliary combustion gas is reduced by using a gas mixed in advance as the auxiliary combustion gas.

In addition, since the flame from the auxiliary combustion gas nozzle 16 is strongly turning, when the swirl flow targets a gas that generates dust by combustion, such as silane gas, combustion-generated silica (SiO ₂ ) is discarded. It serves to prevent attachment to the gas introduction pipe 14 and the auxiliary combustion gas nozzle 16. That is, when the silane (SiH ₄ ) is burned, powdery silica (SiO ₂ ) is produced, but when the silica (SiO ₂ ) adheres to the waste gas introduction pipe 14 or the auxiliary combustion gas nozzle 16, it is assisted. The ejection amount of the combustion gas may be reduced or the ejection direction may be changed to make the ejection unstable. In such a situation, the ejection of the gas is not stabilized and stable combustion is impossible.

In this embodiment, since there is a swirl flame of the auxiliary combustion gas nozzle 16, a rapid flow also occurs at the distal end of the waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 16 by this swing flame. The waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 16 serve to clean the front end, and the produced powder silica (SiO ₂ ) is the waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 16. It acts to prevent it from adhering to the front end. This effect is further remarkable by the presence of the swirling air flow from the air injection nozzle 15.

In addition, this effect is not limited only to the tip of the waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 16. That is, since the flame is turning inside the combustion chamber 30, a rapid flow also occurs on the wall surface of the combustion chamber 30 to clean the wall of the combustion chamber 30 and to remove silica (SiO ₂ ) adhered to the surface. Do it. As described above, the silica (SiO ₂ ) attached to the distal end of the waste gas introduction pipe 14 and the auxiliary combustion gas nozzle 16 and the wall of the combustion chamber 30 is cleaned by swirling flow. To remove SiO ₂ ).

As an example, the auxiliary combustion gas to be supplied uses a premixed gas containing an oxidizing agent and makes the mixing ratio of the oxidant to the combustion gas lower than the oxidizing agent mixing ratio obtained as a stoichiometric value to form a preconcentrated premixed gas which is a fuel overheating, and assists this. Rotational injection from the combustion gas nozzle 16 forms a primary swirl flow reducing flame inside the flame holding unit 18. Waste gas from this reducing flame and waste gas introduction pipe 14 is split to reduce and decompose waste gas, particularly waste gas of PFCs system.

Subsequently, sufficient oxygen exceeding the stoichiometric value is added from the air injected from the air nozzle 15 and the secondary air nozzle 33 to form a secondary oxidized flame in the state of excess oxygen. This oxidizing salt oxidizes the waste gas. In addition, the waste gas is exposed to two stage flames of a reducing flame and an oxidizing flame to prolong the contact time with the flame, thereby extending the high temperature residence time. Here, the waste gas of the PFCs system has properties that can be decomposed when the atmospheric temperature is increased and the high temperature is kept long. In this way, the waste gas can be completely decomposed in the waste gas, in particular, the gas of the PFC system, by being exposed to the flames of the other two stages of oxidation / reduction and extending the high temperature state generated by the flame.

Since the auxiliary combustion gas nozzle 16 is directed downward to the downstream side of the flame holding unit 18, the auxiliary combustion gas is inclined downward so as to form a swirl flow and eject the flame from the auxiliary combustion gas nozzle 16. A spiral swirl flow is formed downstream of the portion 18. Therefore, the turning length when the swirl flows through the inside of the cylindrical member 11 is shorter than when the auxiliary combustion gas is ejected horizontally, and the area where the flame heats the inner wall surface of the cylindrical member 11 is narrowed. The heating and temperature rise of the inner circumferential wall of the cylindrical member 11 are suppressed.

Thereby, the heat resistant life of the constituent material of the cylindrical member 11 can be extended. In addition, the amount of cooling air from the air nozzle 15 can be reduced, thereby reducing the flame temperature caused by cooling and maintaining the high temperature state, thereby improving the decomposition efficiency of halogen-based, especially fluorocarbon waste gas. . Furthermore, when viewed from above, the plurality of auxiliary combustion gas nozzles 16 may be provided in plural so as to open in the tangential direction of the cylindrical member 11 and open obliquely downward in the vertical plane. And such a configuration is also provided so that the flame can form a spiral swirl flow toward the downstream of the flame holding unit 18.

In addition, although the secondary air nozzle 33 faces downward in this embodiment, you may make it spray toward the center direction of the cylindrical member 11, and the air which injects the secondary air nozzle 33 from the nozzle It is also possible to install to form swirl flow in the combustion chamber. By such an arrangement, it is possible to more effectively perform the gas cooling subjected to the combustion treatment, the discharge to the outside of the combustion chamber 30, and further, the removal of silica (SiO ₂ ) adhering to the wall surface of the combustion chamber 30. In this case, the nozzle is installed in the same manner as the auxiliary combustion gas nozzle 16 described above.

In addition, by providing an air spray nozzle at the apex of the cylindrical member 11 and supplying air from the air spray nozzle to the flame holding unit 18 as necessary, the combustibility can be improved.

Further, a secondary combustion air hole is further provided in the circumferential wall of the flame holding portion 18 downstream from the auxiliary combustion gas nozzle 16, so that the flame and the primary combustion flame are reduced in the flame holding portion 18. It is possible to improve the decomposition rate of the waste gas (G1), in particular, a gas containing a halogen-based, in particular fluorocarbon, by forming an oxidized flame of secondary combustion. In this case, for the reasons described above, it is preferable that the air holes are sprayed to form a swirl flow toward the flame holder 18. The cylinder member 11 may be jetted toward the center of the cylindrical member 11 to cause scattering and mixing with the waste gas after the primary combustion by the reducing flame.

In addition, although the flame shows the example which blows down, you may apply when the flame blows out horizontally. The auxiliary combustion gas is not limited to a premixed gas of hydrogen and oxygen, and may be a fuel gas such as hydrogen, city gas, and LPG, or a premixed gas of city gas, LPG and oxygen, air, or oxygen enriched air. Of course.

In one embodiment is as follows.

Gas to be treated; CF ₄

As reductive decomposition in a reducing flame,

CF ₄ + H ₂ → CHmFn + HF + F ₂ (m, n is 0 to 4)

In addition, as an oxidative decomposition reaction,

CHmFn + O ₂ → CO ₂ + H ₂ O

In the combustion chamber 30, the ceramic material constituting the inner wall is excellent in heat resistance and corrosion resistance, so that it is not only consumed by heat or corrosion, but also reinforced by fibers, and cracks due to thermal stress It can be used over a long period of time. In addition, since there is no catalytic effect as in the case of metal, generation of thermal NOx is suppressed even when the combustion chamber 30 is at a high temperature. Even when the halogen-based gas is decomposed, corrosion or etching under high temperature of the inner wall 35 due to the halogen gas (HCl, HF, etc.) generated along with it can be suppressed.

In particular, when using fiber-reinforced ceramics made of alumina, the thermal conductivity under normal operating conditions (600 to 1300 ° C) is about 0.65 to 0.88 (W / mK), and the average of stainless steel or other similar metals is used. It is several hundred times higher than the thermal conductivity = 0.0017 (W / mK). Therefore, the crack due to thermal stress is further reduced. In addition, since the heat-insulating material 37 made of porous ceramic material is arranged around the outer circumference of the inner wall 35, the amount of heat loss can be further reduced than when using a conventional inner wall made of stainless steel or other similar metal. This is the same also when using Si type ceramic material or another ceramic material, for example.

The purge air is introduced from the purge air inlet pipe 40 at a pressure slightly higher than the pressure of the combustion chamber 12 in the space 36 between the outer container 34 and the inner wall 35. The air is blown into the combustion chamber 30 through a minute gap between the inner wall 35 or the end of the inner wall 35, mixed with combustion gas or waste gas, and discharged from the discharge part 52 to the outside. Thereby, the harmful and corrosive gas in the combustion chamber 30 can be prevented from leaking outside from the outer container 34.

As described above, the inner wall 35 of the combustion chamber 30 is formed of a ceramic material to prevent the occurrence of catalytic reaction and achieve low NOx combustion. In addition, if the equivalent ratio of the auxiliary combustion gas is reduced, another low NOx combustion is possible.

The result of comparing the amount of NOx produced in the combustor using the inner wall made of ceramic materials with the case of the combustor using the inner wall of stainless steel is shown below. The conditions such as the type of the combustor are the same for both.

  Combustion temperature: 1300 ℃ or more

Gas to be treated: N ₂ gas

  NOx concentration of exhaust gas

  Inner wall of ceramic material: 25 ppm

  Inner wall of stainless steel: 100 to 1000 ppm

3 and 4 are views showing another configuration example of the burner portion of the waste gas treatment apparatus of the present invention, FIG. 3 is a longitudinal sectional view, and FIG. 4 is a view seen from the arrow A of FIG. In the drawings, the same reference numerals as in Fig. 1 and Fig. 2 denote the same or corresponding parts. The same applies to the other drawings. The burner part 10 includes a cooling jacket 21 provided adjacent to the auxiliary combustion gas chamber 20 at the outer circumference of the cylindrical member 11. The cooling medium is supplied to the cooling jacket 21. By supplying a cooling medium to the cooling jacket 21, the cooling jacket 21 cools the cylindrical member 11 heated by the flame formed in the opening. The cooling medium may be any one having a temperature difference, and a liquid such as water or a gas such as air is used.

The pilot burner 39 is inclined at a predetermined angle to the apex portion of the cylindrical member 11 (the ceiling plate of the burner section 10). This is because the auxiliary combustion gas (flame) injected from the auxiliary combustion gas nozzle 16 becomes shorter in the radial direction, so that the pilot burner may be inclined at a predetermined angle.

In the combustion burner part 10 of the combustor shown in FIG. 1, the internal temperature of the cylindrical member 11 rises to 400 degreeC, but in the case of water cooling, it falls to 70 degreeC in this burner part 10 especially. Therefore, there is no risk that the auxiliary combustion gas held in the auxiliary combustion gas chamber 20 will ignite and explode. However, since the secondary air nozzle is not provided as described above, the air is increased by increasing the primary air from the air nozzle 15 or by increasing the amount of pre-mixed O ₂ . In this case, the air nozzle 15 is installed with the oblique side facing downward, and the swirling air flow is formed obliquely downward, but the air nozzle 15 is horizontally installed as shown in FIG. Naturally, it may be allowed to form a stream.

By using the burner unit 10 as a cooling structure as described above, the temperature of the cylindrical member 11 is lowered, but C ₂ F ₆ which is a hardly decomposable gas (the gas has a global warming coefficient of 10,000 times CO ₂ As a countermeasure against warming, it is desired to decompose 100%). This is considered to be because the temperature of the burner part 10 falls and a flame temperature falls by this. Therefore, the structure of the burner part which can cool effectively the fuel gas introduction part which introduce | transduces auxiliary combustion gas into the auxiliary combustion gas nozzle 16 which is heated to high temperature and poses a risk of explosion is demonstrated below.

5 and 6 are views showing another configuration example of the burner section of the waste gas treatment apparatus according to the present invention, FIG. 5 is a longitudinal cross-sectional view, and FIG. 6 is a view seen from the direction of an arrow D in FIG. The burner part 10 is provided with an air chamber 22 around the upper outer circumference of the cylindrical member 11, and again the cooling outer cylinder 24, the auxiliary combustion gas chamber 23 and the cooling jacket 24 on the lower outer circumference. It is installed concentrically. The inner peripheral wall of the cylindrical member 11 is provided with an air nozzle 15 communicating with the air chamber 22, and the auxiliary combustion gas chamber 23 communicates with the auxiliary combustion gas chamber 23 on the lower surface of the auxiliary combustion gas chamber 23. The nozzle 16 is provided.

The auxiliary combustion gas from the auxiliary combustion gas nozzle 16 is sprayed downward or obliquely downward to the central portion below the opening of the cylindrical member 11 to form a swirl flow as indicated by the arrow B. FIG. Moreover, the air injected from the air nozzle 15 forms the swirl flow which turns in the cylindrical member 11, as shown by the arrow C.

The process gas G1 introduced into the cylindrical member 11 in the burner section 10 having the above-described configuration is mixed with the swirling air flow from the air nozzle 15, and the burner section (from the auxiliary combustion gas nozzle 16). A flame is formed toward the bottom of the opening of the cylindrical member 11 by mixing with the auxiliary combustion gas injected downward of 10). At this time, the auxiliary combustion gas chamber 23 is cooled by the cooling jacket 24 from both sides, and the temperature is kept low. In addition, since the flame is formed below the cylindrical member 11, the temperature decrease of the cylindrical member 11 does not greatly affect the flame.

7 and 8 are views showing another configuration example of the burner section of the waste gas treatment apparatus according to the present invention, FIG. 7 is a longitudinal sectional view, and FIG. 8 is a view seen from the direction of the arrow E in FIG. The burner section 10 differs from the burner section 10 shown in FIGS. 5 and 6 in that the auxiliary combustion gas chamber 23 is provided in the cooling jacket 24 provided at the outer circumference of the cylindrical member 11. The surroundings of the auxiliary combustion gas chamber 23 are surrounded by a cooling medium. Further, an auxiliary combustion gas nozzle 16 communicating with the auxiliary combustion gas chamber 23 is provided on the lower surface of the auxiliary combustion gas chamber 23.

The sub-combustion gas from the sub-combustion gas nozzle 16 is sprayed toward the center of the lower part of the opening of the cylindrical member 11 or obliquely downward and also in a swirling flow as indicated by the arrow B. As shown by the arrow C, the air injected from 15) is the same as the burner part 10 shown in FIG. 5 and FIG. 6 in that the swirl flow which turns in the cylindrical member 11 is formed.

In the burner section 10 having the above configuration, the waste gas G1 to be treated introduced into the cylindrical member 11 is mixed with the swirling air flow from the air nozzle and burner section from the auxiliary combustion gas nozzle 16. The flame is mixed with the auxiliary combustion gas injected downward of the (10) and is formed by extending the flame toward the bottom of the opening of the cylindrical member (11) by ignition. At this time, since the auxiliary combustion gas chamber 23 is surrounded by the cooling medium in the cooling jacket 24, the auxiliary combustion gas chamber 23 is cooled and the temperature is kept low. In addition, since the flame is formed downward from the cylindrical member 11, the temperature drop of the cylindrical member 11 does not significantly affect the flame as in the case of the burner part 10 shown in Figs.

9 and 10 are views showing another configuration example of the burner section of the waste gas treatment apparatus according to the present invention, FIG. 9 is a longitudinal sectional view, and FIG. 10 is a view seen from an arrow F in FIG. The burner part 10 differs from the burner part 10 shown in FIGS. 5 and 6 by the cylindrical auxiliary combustion gas chamber 25 in the cooling jacket 24 formed around the lower outer periphery of the cylindrical member 11. I'm doing it. In the cylindrical auxiliary combustion gas chamber 25, an auxiliary combustion gas nozzle 16 is installed at the front end, and each auxiliary combustion gas nozzle 16 is inclined so as to extend from the lower end of the auxiliary combustion gas nozzle 16 so as to extend through the cooling jacket 24. .

The sub-combustion gas from the sub-combustion gas nozzle 16 is sprayed toward the center of the lower part of the opening of the cylindrical member 11 or obliquely downward and also in a swirling flow as indicated by arrow B. As shown by arrow C, the air injected from 15) becomes the swirl flow which turns in the cylindrical member 11, and is almost the same as the burner part 10 shown in FIG.

The waste gas G1 to be treated introduced into the cylindrical member 11 in the burner portion having the above configuration is mixed with the swirling air flow from the air nozzle 15 and the burner portion 10 from the auxiliary combustion gas nozzle 16. A flame is formed toward the bottom of the opening of the cylindrical member 11 by mixing with the fuel gas injected below the bottom. At this time, the cylindrical auxiliary combustion gas chamber 25 is cooled because the outer periphery is surrounded by the cooling medium in the cooling jacket 24, so that the temperature is maintained at a low level. In addition, since the flame is formed below the cylindrical member 11, the temperature drop of the cylindrical member 11 does not significantly affect the flame as in the burner section 10 shown in Figs.

11 and 12 are views showing another configuration example of the burner section of the waste gas treatment apparatus according to the present invention, FIG. 11 is a longitudinal sectional view, and FIG. 12 is an external view of the cooling jacket 26. The burner part 10 differs from the burner part 10 shown in FIGS. 5 and 6 by the fact that the cooling jacket 26 is provided around the lower outer periphery of the cylindrical member 11, and the cylindrical shape is formed in the cooling jacket 26. The auxiliary combustion gas chamber 27 of the upper stage is arrange | positioned. At the tip of the cylindrical auxiliary combustion gas chamber 27, an auxiliary combustion gas nozzle 16 is inclined and extends downward from the opening of the cylindrical member 11 and has a predetermined angle with respect to the tangential direction of the inner circumferential surface. have.

The auxiliary combustion gas from the auxiliary combustion gas nozzle 16 is injected to form a swirl flow downwardly or obliquely downward toward the central portion below the opening of the cylindrical member 11, as indicated by the arrow B. FIG. Moreover, the air injected from the air nozzle 15 is made to pivot in the cylindrical member 11 similarly to the case of the burner part 10 shown to FIG. 5 and FIG.

The gas to be processed introduced into the cylindrical member 11 in the burner part 10 having the above-described configuration is mixed with the swirling air flow from the air nozzle 15 and at the same time, the burner part 10 is discharged from the auxiliary combustion gas nozzle 16. It is mixed with the auxiliary combustion gas injected to the bottom of the) is formed so that the flame extends toward the bottom of the opening of the cylindrical member 11 by ignition. At this time, since the auxiliary combustion gas chamber 27 is surrounded by the cooling water of the cooling jacket 21 on the outer circumference thereof, the auxiliary combustion gas chamber 27 is cooled and the temperature is kept low. In addition, since the flame is formed downward from the cylindrical member 11, the temperature drop of the cylindrical member 11 does not significantly affect the flame as in the case of the burner part 10 of Figs.

When the waste gas containing SiH ₄ or the like is thermally decomposed in a combustor to make it harmless, dust such as SiO ₂ is generated, and the dust is formed on the inner wall of the cylindrical member 11 of the burner unit 10 or the combustion chamber 30. There is a gas which is attached to the inner wall of the pipe and the inner wall of the pipe after the combustion chamber, causing a problem of increasing the exhaust pressure loss. Therefore, the waste gas burner of the waste gas treating apparatus of the present invention is provided with a dust removing apparatus for removing dust attached to the inner wall thereof.

It is a figure which shows the structural example of a dust remover. As shown in the drawing, a scraping plate 56 provided at the tip of the shaft 57 vertically moving between the burner section 10 and the combustion chamber 30 is installed in the dust removing apparatus. By moving the scraping plate 56 vertically, the dust adhering to the inner wall surfaces of the burner section 10 and the combustion chamber 30 is scraped off. As shown in Figs. 14A and 14B, the scraping plate 56 is provided with a round hole 56a or a linear hole 56b larger than the opening of each waste gas introduction pipe 14. As a result, when the scraping plate 56 is raised to the retracted position of the uppermost portion (solid line position in FIG. 13), the hole 56a is located corresponding to the opening of the waste gas introducing pipe 14, and the waste gas introducing pipe 14 ) So as not to interfere with the flow of waste gas flowing into burner section 10 (cylinder member 11). When the scraping plate 56 is raised to this retracted position, the scraping plate 56 does not interfere with the swirl flow of air blown out from the air nozzle 15 and the auxiliary combustion gas nozzle 16 and the swirl flow of the auxiliary combustion gas.

At the lower end of the combustion chamber 30, a cooling receiver 44 which cools the waste gas combusted in the combustion chamber 30 and receives dust that has been scraped off by the scraping plate 56 is provided, and the cooling receiver 44 A shut-off valve 45 is provided at the lower end of the valve, and a dust storage tank 47 is installed at the lower end of the shut-off valve 45 via a clamp 46. In addition, an exhaust pipe 54 and a drain port 52 are provided in the cooling receiver 44. Moreover, the U trap 58 is connected to the dust storage tank 47 via the valve V1, and the drain pipe 59 is connected to the U trap via the valve V2.

In the dust removing apparatus having the above-described configuration, when it is detected that a predetermined amount of dust adheres to the inner wall surfaces of the burner section 10 and the combustion chamber 30, the shaft 57 is moved manually or automatically, and the scraping plate 56 is removed. The attached dust is scraped off into the cooling receiver 44 by using < RTI ID = 0.0 > In the cooling receiver 44, the valve V3 is opened, the dust is collected by the drain port 52, the dust is collected, and when the dust is a predetermined amount, the closing valve 45 is opened and the dust is put into the dust storage tank 47. Then, the closing valve 45 is closed, and the valves V1 and V2 are opened to drain wastewater in the dust storage tank 47 through the drain pipe 59 via the U trap 58. The reason why the U trap 58 is provided here is that when the wastewater is directly discharged to the drain pipe 59, the harmful gas is discharged at the same time.

In addition, the dust scraping operation monitors the amount of dust attached (for example, a pressure sensor for detecting the pressure in the combustion chamber 30, a temperature sensor for detecting the wall temperature of the combustion chamber 30, and a dust amount attached to the inner wall surface). Monitor device, and if the amount of attachment is a predetermined amount, the shaft 57 may be automatically moved vertically to scrape the dust, and a timer may be provided to allow the shaft 57 to be decremented. It may be used to scrape dust. In addition, the scraping plate 56 and the like are made of a corrosion resistant, heat resistant material such as a ceramic material.

In addition, although the illustration of the dust storage tank 47 is omitted, a dust observation sensor and dust storage tank 47 such as a transparent observation window for checking the amount of dust accumulated therein or a photoelectric sensor for detecting a predetermined amount of dust accumulated therein If a water supply pipe for supplying water is provided and a predetermined amount of dust accumulates in the dust storage tank 47, the closing valve 45 is closed and the valves V1 and V2 are opened to open the dust storage tank 47 from the water supply pipe. The dust in the dust accommodating tank 47 may fall through the U trap 58 by washing the dust into the dust.

Also, without installing the drain port 52, the closing valve 45 and the valves V1 and V2 are opened to drop water and dust from the cooling receiver 44 into the dust storage tank 47, and the water is U. The water may be drained through the trap 58.

In the structural example of FIG. 13, the scraping plate 56 is vertically moved between the burner portion 10 and the combustion chamber 30, but as shown in FIG. 15, only the burner portion 10 may be vertically moved. . In addition, the evacuation position is not limited to the upper portion of the burner section 10. For example, a drive device for moving the shaft 57 to move the shaft 57 is provided below the combustion chamber 30 or the cooling receiver 44, and the evacuation position is provided. The bottom part of the combustion chamber 30 may be used.

15 is a diagram illustrating another configuration example of the dust removing apparatus. As shown in the drawing, the dust removing device is provided with a scraping device having a structure in which a scraping plate 56 is provided at the tip of the shaft 57 as shown in FIG. It is configured to scrap dust attached to the inner wall by the shanghai-dong. Moreover, the ring-shaped air chamber 41 is provided in the upper part of the combustion chamber 30, and many air injection nozzles 42 are provided from the lower surface of the air chamber 41 as shown in FIG. The air attached to the inner wall surface of the combustion chamber 30 is blown off by blowing air downward or obliquely downward along the wall surface of the combustion chamber 30 from the air injection nozzle 42. In addition, a layer of airflow flowing from top to bottom is formed, and the layer of airflow prevents adhesion of dust to the inner wall surface.

Although not shown in the lower part of the combustion chamber 30, the cooling receiver 44 etc. are provided like FIG. Similar to the dust removal apparatus of FIG. 13, the shank-and-move of the shaft 57 is performed manually or automatically, or every predetermined time of operation by a timer.

In addition, in the above-described example, the dust attached to the inner wall of the burner unit 10 is scraped off by the scraping plate 56 fixed to the shaft 57, and the air is blown out along the inner wall surface of the combustion chamber 30. Although it is configured to blow off the attached dust or form an air flow layer to prevent the adhesion of dust, an air flow layer is formed on the inner wall surfaces of both the burner part 10 and the combustion chamber 30 to prevent the adhesion of dust. It may be prevented.

In addition, by intermittently ejecting air from the air injection nozzle 42, the dust adhering to the inner wall surface can be removed with a minimum amount of blowing air.

17 and 18 are views showing another configuration example of the dust removing apparatus, FIG. 17 is a longitudinal sectional view of the combustion chamber, and FIG. 18 is a sectional view seen in the III-III direction of FIG. The inner wall 35 is formed of a porous material (for example, a plurality of fine holes are formed in a particulate filter, a porous ceramic material, and a heat resistant plate material) and an inner wall 35 and an outer container 34 made of the porous material. A plurality of independent annular air chambers 36 'are provided in between. Each air chamber is connected to a source of air, and air is uniformly blown into the combustion chamber 30 from many holes in the inner wall 35 by supplying compressed air from the air source. This blowing out of the air prevents the dust adhering to the inner wall or the dust adhering to the inner wall 35 uniformly.

In the dust removing apparatus of the above configuration, the air may be ejected from the holes of the inner wall 35 continuously while the waste gas treating apparatus is operated. In some cases, a predetermined amount of dust adheres to the inner wall. In this case, the detection means may be used to blow off air to remove the dust. In addition, air may be blown out every predetermined time.

19 is a longitudinal cross-sectional view showing a configuration example of a dust removing apparatus for removing dust adhered to an inner wall of a pipe when a gas containing dust flows. As shown in the drawing, the dust removing apparatus is provided with a scraping mechanism having two rod-shaped scraping members 63 extending in the longitudinal direction of the main shaft 62. The waste gas G3 containing dust flows. It is arrange | positioned in the piping 61. Seal support having a sealing function while supporting the main shaft 62 of the scraping mechanism so that the scraping member 63 contacts the inner surface of the pipe 61 or is positioned with a small gap. A mechanism 64 and a drive device 65 for rotating the scraping mechanism continuously or periodically about a main shaft 62 to swing or rotate.

The main shaft 62 and the scraping member 63 are hollow pipes, and the hollows of each other communicate with each other through a joint 66 such as a rotary joint, so that the clean gas G4 is hollowed and scraped from the main shaft 62. It blows into the piping 61 from the front end (upper end) of the scraping member 63 via the hollow part of the member 63. As shown in FIG. The dust collecting part 67 is installed in the lower end of the piping 61, and the water spray nozzle 69 which sprays water is installed in the inner wall surface of the dust collecting part 67, and the bottom of the dust collecting part 67 is provided. The drain pipe 70 is provided in the part.

In the dust removing apparatus of the above structure, the gas G3 containing the dust flowing into the pipe 61 is discharged through the exhaust pipe 68, but the dust is attached to the pipe 61. When the scraping mechanism is rocked or rotated continuously or periodically about the main shaft 62 by the drive device 65, the dust adhered to the inner wall of the pipe 61 is scraped by the scraping member 63, thereby causing dust. It falls to the receiving part 67. At this time, by spraying clean gas G4, such as air, continuously or intermittently from the tip of the scraping member 63, dust in the range that the scraping member 63 does not reach is also removed.

  Since the dust removed in this way falls on the dust collecting section 67 in the form of fine particles, when water is sprayed from the water spray nozzle 69 on this portion, the dust is discharged from the drain pipe 70 without being blocked. . When the waste gas G1 is a corrosive gas, mixing ammonia gas with the clean gas G4 can neutralize the inner surface of the pipe 61 to prevent the progress of corrosion.

FIG. 20 is a diagram showing an example of the configuration in the case where the dust removing apparatus having the configuration shown in FIG. 19 is installed in the waste gas burner of the waste gas treating apparatus. As shown in the figure, a scraping mechanism having a structure in which two rod-shaped scraping members 73 extending in the longitudinal direction of the main shaft 72 are provided in the combustion chamber 30 through which the waste gas G1 flows from the semiconductor manufacturing equipment. And a seal support having a sealing action while supporting the main shaft 72 of the scraping mechanism so that the scraping member 73 contacts the inner surface of the combustion chamber 30 or moves in the inner circumferential direction at a slight interval. A mechanism 74 and a drive unit 75 that swings or rotates the scraping mechanism continuously or periodically about the main shaft 72.

In addition, the clean gas G4 forms the combustion chamber 30 from the upper end of the scraping member 73 through the hollow portion of the main shaft 72 and the hollow portion of the scraping member 73 via a joint 76 such as a rotary joint. It is made to blow into the piping 71 to be made. The burner 81 is installed in the upper burner part 10 of the inner wall surface of the combustion chamber 30, and the cooling receiver 77 is installed in the lower end of the combustion chamber 30, and the exhaust port (side) of the cooling receiver 77 is provided. 78) is installed. In addition, a water spray nozzle 79 for spraying water is provided on the inner wall surface of the cooling receiver 77. Moreover, the drain port 80 which communicates with the inside of the cooling receiver 77 is provided in the lower end part.

The waste gas G1 from the semiconductor manufacturing facility or the like is heated and harmless by the flame formed by the burner 81 to become a high temperature waste gas containing a high concentration of dust. Since the temperature of the flame 82 formed by the burner 81 reaches about 2000 degreeC, when an object touches the flame 82 directly, most substances will melt | dissolve. For this reason, since the wall surface temperature in the combustion chamber 30 immediately after the burner 81 is lower than 2000 degreeC, dust adheres and it becomes easy to produce clogging. The same applies to the vicinity of the burner section 81.

Under the above circumstances, when the scraping mechanism is rotated or oscillated about the main shaft 72 by the driving device 75, the scraping member 73 can directly scrape the dust attached to the inner wall surface of the combustion chamber 30. This prevents clogging due to adhesion of dust. In addition, even in the range where the scraping member 73 cannot be inserted because the flames 82 touch, the clean gas G4 is supplied through the joint 76 such as a rotary joint to eject from the upper end of the scraping member so that the inner wall surface You can remove dust attached to it.

The waste gas G1 heated and combusted by the flame 82 flows into the cooling receiver 77 and is cooled by water injected from the water spray nozzle 79 to be discharged from the exhaust port 78 and scraped at the same time. Water containing dust is discharged from the drain 80.

FIG. 21 is a diagram showing another configuration example of the main shaft 72 and the scraping member 73 of the scraping mechanism. As shown in the figure, a plurality of small holes 73a are provided on the outer circumferential surface of each scraping member 73 in communication with the hollow portion therein. The clean gas G4 is supplied through the hollow portion 76 of the rotary joint or the like through the hollow portion of the main shaft 72 and the scraping member 73 so that the clean gas G4 passes through the hole 73a. While ejecting to the inner wall of the combustion chamber 30, it also ejects from the upper end of the scraping member 73. Thereby, dust attached to the range of the clearance d between the scraping member 73 and the inner wall surface of the combustion chamber 30 can also be removed by blowing.

FIG. 22 is a diagram showing another configuration example of the scraping mechanism composed of the main shaft 72 and the scraping member 73. As shown in FIG. As shown in the figure, a plurality of small holes 73a and 72a communicating with the hollow part are provided on the entire surface of the scraping member 73 or the main shaft 72 as shown. With such a configuration, dust is introduced into the gap between the scraping member 73 and the inner wall surface of the combustion chamber 30 by introducing clean gas G4 into the hollow portion of the main shaft 72 and the scraping member 73. It is possible to remove by blowing. In addition, the dust adhering to the main shaft 72 and the scraping member 73 itself can be blown off and removed.

In addition, although the hole 72a, 73a which communicates with a hollow part is provided in the surface of the main shaft 72 or the scraping member 73 in the example of FIG. 21 and FIG. 22, these hole 72a, 73a is provided. Instead of this, a slit communicating with the hollow portion may be provided. In addition, the structure of the scraping mechanism of FIG. 15 and FIG. 16 is naturally applicable to the scraping mechanism which consists of the main shaft 62 and the scraping member 63 of FIG.

In addition, the number of scraping members 73 of the scraping mechanism need not be limited to two, and as shown in FIG. 23, three scraping members 13 may be provided on the main shaft 72. More than one may be sufficient. 19, three or more scraping members may be provided in the main shaft 62, and the scraping mechanism may be comprised.

By increasing the number of the scraping members 73 to three or more, the number of dust scrapings per one revolution of the scraping mechanism is increased to cope with the case where the dust concentration is high. In addition, when the scraping mechanism performs the reciprocating rotation of the predetermined angle, dust of all regions can be scraped even if the swing angle is reduced. However, if the scraping member 73 is made extremely large, there is a fear that the combustion chamber 30 may be blocked by dust attachment to the scraping mechanism itself.

Although not shown, a scraping mechanism having the configuration shown in FIGS. 20 to 23 is installed in the waste gas treatment combustor shown in FIG. 1 to remove dust adhering to the inner wall of the burner unit 10 and the combustion chamber 30. It may be configured.

In the dust removal apparatus of the structure shown to FIGS. 19-23, the gas G1 or G3 which flows into the piping 61, the flame | frame holding part 10, and the combustion chamber 30 is not only dust but also the piping 61, When the flame holding part 10 and the inner wall of the combustion chamber 30 contain the component which may erode by the action of corrosion etc., when gas which has a property which neutralizes the action to clean gas G4 is introduced, (For example, an alkaline gas such as ammonia is introduced into the inflow of acid gas.) The erosion effect of the pipe can be suppressed in the range of the clean gas G4.

24 and 25 are views showing another configuration example of the burner section of the waste gas treatment apparatus of the present invention, FIG. 24 is a longitudinal sectional view, and FIG. 25 is a view seen from the direction of an arrow L in FIG.

The burner part 10 reduces the height H of the flame holding part 18 compared with the burner part 10 of FIGS. 3 and 4, and again, the air nozzle 15 and the auxiliary combustion gas nozzle. The space | interval I between (16) is made small. In other words, the air outlet of the air nozzle 15 is as close as possible to the auxiliary combustion gas outlet of the auxiliary combustion gas nozzle 16. Moreover, the space | interval J of the tangent of the center line of the air nozzle 15 and the inner wall surface is made small so that the air blown out from the air nozzle 15 may approach the tangent of the inner wall surface of the cylindrical member 11.

Thus, the height H of the flame | maintaining part 18 is made small, and the space | interval I between the air nozzle 15 and the auxiliary combustion gas nozzle 16 is made small, and it is made between the valley of an air outlet and an auxiliary combustion gas outlet. The flow of dust is eliminated, and the dust attached to or to be attached to the inner wall surface of the flame holding unit 18 is blown off by the air flow to prevent the attachment to the inner wall surface as much as possible.

In addition, since the air blown out from the turning nozzle 15 approaches the tangential of the inner wall surface of the cylindrical member 11, dust is adhered to the inner wall surface by preventing the flow of flow near the inner wall surface of the cylindrical member 11. Becomes difficult.

Moreover, the air nozzle 15 was provided so that the flow of air blown out from the air nozzle 15 may incline from horizontal to downstream. When the inclination angle θ1 with respect to the horizontal plane of the air nozzle 15 is about 30 °, the dust adhesion prevention effect near the auxiliary combustion gas nozzle 16 is large. In addition, the air nozzle 15 is provided with a plurality of air ejection ports so as to evenly open in the circumferential direction of the inner wall surface of the cylindrical member 11, the air flow with a high flow rate immediately after the high blowing effect is evenly spread throughout the inner wall surface I'm trying to.

The air introduction angle θ2 in the horizontal direction of the air nozzle 15 is θ2 = 360 ° / n. N is the number of air nozzles 15 arranged in the circumferential direction, and is an integer of 3 or more. In particular, the number of air nozzles (n) was good at 4, 8, 12, 16 and 24.

The ratio H / K of the inner diameter K to the height H of the flame holding part 18 is 15 mm / 80 mm here compared with what was conventionally 50 mm / 80 mm. In addition, the space | interval I between the lower air nozzle 15 and the upper auxiliary combustion gas nozzle 16 is set to 16 mm here compared with what was conventionally 26 mm. Even if the inner diameter K increases or decreases, the interval I is constant. In addition, the space | interval J of the tangent of the center line of each air nozzle 15 and the inner wall surface parallel to the center line is 5 mm here compared with what was conventionally 15 mm.

It is a longitudinal cross-sectional view which shows the other structural example of the burner part of the waste gas processing apparatus of this invention. As shown in the drawing, the inner diameter of the opening portion 14a of the waste gas introduction pipe 14 gradually increases downward, and the inner diameter of the cylindrical member 11 gradually increases downward. Thereby, the angle part like a right angle disappears in the opening part 14a of the waste gas introduction pipe 14, and the inside of the cylindrical member 11. As shown in FIG. Further, an inverted frusto-conical projection may be provided between the openings 14a of the waste gas introduction pipe 14.

In the burner part 10, dust adheres to the angled part or to the part where the air or waste gas stays. Here, as described above, the angled portions formed at right angles in the openings 14a of the waste gas introduction pipe 14 and the cylindrical member 11 are eliminated, and the waste gas is trapped between the waste gas introduction pipes 14. As it disappears, it becomes difficult for dust to adhere to the inner wall surface.

As described above, according to the invention of Claims 1 to 3, since the combustion chamber is formed of the inner wall of the fiber-reinforced ceramic material, the inner wall is less consumed by heat or corrosion, and the occurrence of cracking due to thermal stress is also reduced. The lifetime is improved, the equipment cost and the operation rate can be improved, and since the inner wall does not exhibit a catalytic effect, the generation of thermal NOx can be suppressed and the environment can be conserved and the processing equipment can be simplified. Therefore, the overall compact and low cost waste gas treatment apparatus can be provided.

In addition, according to the invention of claim 3, since the space between the inner wall and the outer container is maintained in a purge gas atmosphere at a pressure higher than that of the combustion chamber, it is possible to prevent leakage of harmful gases in the combustion chamber to the outside.

Further, according to the inventions of claims 4 to 9, since the cooling means for cooling the auxiliary combustion gas introduction unit for introducing the auxiliary combustion gas is installed in the auxiliary combustion gas nozzle of the burner unit, even if the auxiliary combustion gas introduction unit is heated by the flame, the temperature rise is increased. By suppressing below the ignition point of the auxiliary combustion gas, there is no risk of explosion of the auxiliary combustion gas.

In addition, according to the inventions of claims 6 to 9, since the flame does not directly contact the cooling jacket, the heat amount of the flame by the cooling medium is reduced, and a large amount of heat can be used for waste gas treatment.

According to the invention of Claims 10 to 13, since the dust removal means for removing the dust attached to the burner portion and / or the inner wall of the combustion chamber or preventing the dust from adhering is provided, clogging the burner portion and / or the combustion chamber with dust. It is possible to operate the waste gas treatment system for a long time without.

According to the invention as set forth in claim 14, the dust adhering in the pipe is removed by rocking or rotating continuously or periodically with the scraping mechanism disposed in the pipe, so that the exhaust gas in the pipe can flow with the minimum pressure loss.

In addition, according to the invention of Claims 15 to 18, the scraping member and the main shaft are each made of a hollow pipe from the outside of the pipe through the hollow of the main shaft and the scraping member from a plurality of holes or slits at the tip of the scraping member or its surface. By blowing the clean gas, not only the dust in the pipe which the scraping member does not reach can be removed, but also the dust attached to the scraping mechanism itself can be removed. In addition, when hot gas flows through the pipe, the durability of the device itself is improved by the cooling effect of the clean gas.

According to the invention described in claim 17, since neutralizing gas that neutralizes the gas flowing in the pipe is used as the clean gas, when the corrosive gas flows through the pipe at a high temperature, not only the cooling effect but also the corrosion preventing effect of the pipe is expected. Can be.

Further, according to the invention of Claims 19 to 21, since the air nozzle is an air nozzle configured to eject a swirling air flow downward in a combustion flame formed toward the lower part of the opening, waste gas treatment in which dust is hard to adhere to the inner wall of the nozzle part. It becomes a device.

According to the invention as set forth in claim 22, since the inner diameters of the waste gas inlet and the cylindrical member gradually increase toward the combustion chamber, there is no angled portion such as a portion at right angles in the burner portion, and the waste gas hardly adheres to the inner wall of the nozzle portion. It becomes a processing device.

According to the invention as set forth in claim 23, it is possible to provide a waste gas treatment system that can compactly and efficiently treat waste gas containing harmful combustible gas or hardly decomposable gas.

Claims (23)

A burner section having a burner section and a combustion chamber provided downstream of the burner section, forming a combustion flame from the burner section toward the combustion chamber, and introducing waste gas into the combustion flame to oxidatively decompose the waste gas. In the apparatus, And said combustion chamber is formed of an alumina continuous fiber inner wall woven into a cloth and coated with a ceramic material containing a binder and solidified into a cylindrical shape. The method of claim 1, And a heat insulating material made of porous ceramic material between the inner wall and the outer container of the combustion chamber. The method of claim 2, And a purge gas supply means for maintaining a space between the inner wall and the outer container with a purge gas atmosphere having a pressure higher than that of the combustion chamber. A waste gas treatment apparatus having a burner portion and a combustion chamber provided downstream of the burner portion, forming a combustion flame from the burner portion toward the combustion chamber, and introducing waste gas into the combustion flame to oxidatively decompose the waste gas. To The burner part is provided with a cylindrical member having a top part closed and an opening part at a lower part thereof, a waste gas inlet port provided at the top part of the cylindrical member, and an air nozzle at a predetermined position of the side wall thereof, An auxiliary combustion gas nozzle is installed on the adjacent side wall to mix the waste gas introduced from the waste gas inlet and the air blown out from the air nozzle to ignite the auxiliary combustion gas ejected from the auxiliary combustion nozzle to combust downward. To form a flame, And a cooling means for cooling the auxiliary combustion gas introduction unit for introducing fuel gas into the auxiliary combustion gas nozzle is provided around the burner unit. The method of claim 4, wherein The auxiliary combustion gas introducing unit is an auxiliary combustion gas chamber provided on the outer circumferential side of the cylindrical member, and the auxiliary combustion gas nozzle is installed inside the auxiliary combustion gas chamber to eject the auxiliary combustion gas toward the center of the combustion chamber, and the cooling is performed. And means for cooling the auxiliary combustion gas chamber by supplying a cooling medium to the cooling jacket provided at the boundary between the auxiliary combustion gas chamber and the combustion chamber. The method of claim 4, wherein The auxiliary combustion gas introduction portion is an auxiliary combustion gas chamber provided on the outer circumferential side of the cylindrical member, and the auxiliary combustion gas nozzle is installed in the lower portion of the auxiliary combustion gas chamber to eject the auxiliary combustion gas together with the swirling air flow into the combustion chamber. And the cooling means is configured to cool the auxiliary combustion gas chamber by supplying a cooling medium to a cooling jacket provided adjacent to the auxiliary combustion gas chamber and installed at an outer circumference of the auxiliary combustion gas chamber. The method of claim 4, wherein The auxiliary combustion gas introduction portion is an auxiliary combustion gas introduction pipe having the auxiliary combustion gas nozzle installed at the tip thereof, and the auxiliary combustion gas introduction pipe is installed at an outer circumference of the lower end of the cylindrical member to extend through a cooling jacket, and the auxiliary combustion gas introduction pipe is extended. The combustion gas nozzle is arranged so that the auxiliary combustion gas is ejected toward the center of the combustion chamber, and the cooling means is arranged to supply a cooling medium to the cooling jacket to cool the auxiliary combustion gas introduction pipe. Device. The method of claim 4, wherein The auxiliary combustion gas introduction portion is an auxiliary combustion gas introduction pipe having the auxiliary combustion gas nozzle installed at the tip, and the auxiliary combustion gas introduction pipe is connected to the combustion chamber from the auxiliary combustion gas nozzle at the outer circumference of the lower end of the cylindrical member. The cooling means is arranged through a cooling jacket installed at an outer circumference of the auxiliary combustion gas introduction pipe to supply a cooling medium to the cooling jacket to cool the auxiliary combustion gas introduction pipe. Waste gas treatment apparatus characterized in that the configuration. The method according to any one of claims 4 to 8, Waste gas treatment apparatus, characterized in that the cooling medium is any one of water, air, or other liquid, gas. A waste gas treatment apparatus including a burner portion and a combustion chamber provided downstream of the burner portion to form a combustion flame from the burner portion toward the combustion chamber, and introduce waste gas into the combustion flame to oxidatively decompose the waste gas. To To install the dust removal means for preventing the removal of dust attached to the burner or the combustion chamber inner wall, The dust removing means blows the air upwards so that an air flow layer is formed along the inner wall of the burner or the inner wall of the combustion chamber, and the air flow layer adheres to the inner wall surface of the burner or the inner wall of the combustion chamber. Waste gas treatment apparatus, characterized in that to prevent being. delete delete The method of claim 10, The dust removing means includes an air spray nozzle which forms an air flow layer along the inner wall surface of the burner part or the combustion chamber, and injects air continuously or intermittently from the air spray nozzle to form the air flow layer. Waste gas treatment device. In the dust removal device for removing the dust adhering to the inner wall of the pipe flowing a lot of dust gas, The scraping mechanism having a rod-shaped scraping member disposed in the pipe and extending in the longitudinal direction of the pipe, and the main shaft of the scraping device contacts the inner surface of the pipe or makes a slight gap. And a support mechanism for moving so as to move in an inner circumferential direction, and a driving device for oscillating or rotating the scraping mechanism continuously or periodically about a main axis, The rod-shaped scraping member blows air upward so that an air flow layer is formed along the inner wall of the pipe, so that the air flow layer prevents dust from adhering to the inner wall of the pipe. Removal device. The method of claim 14, The scraping member and the main shaft are made of respective hollow pipes, and the hollow of the scraping member and the main shaft is in communication with each other, and an opening is provided at the tip of the scraping member to communicate with the hollow. The dust removing device, characterized in that supplied through the hollow of the spindle and the scraping member and blows out a clean gas from the opening. The method according to claim 14 or 15, Each of the scraping member and the main shaft is made of a hollow pipe, and each of the scraping member and the main shaft is in communication with each other, and both the scraping member and the main shaft are in communication with the hollow part on the surface of the scraping member. And a plurality of holes or slits so that clean air is supplied through the hollow of the spindle and the scraping member from the outside of the pipe and blows clean gas out of the plurality of holes or slits. The method of claim 15, Dust removing device, characterized in that for using the neutralizing gas to neutralize the gas flowing in the pipe as the clean gas. The method of claim 15, The dust removal device, characterized in that the clean gas is ejected continuously or intermittently. delete delete delete A burner section having a burner section and a combustion chamber provided downstream of the burner section, forming a combustion flame from the burner section toward the combustion chamber, and introducing waste gas into the combustion flame to oxidatively decompose the waste gas. In the apparatus, The burner part includes a cylindrical member having a top portion closed and an opening portion at a lower portion thereof, a waste gas inlet at the top portion of the cylindrical member, and a plurality of air nozzles at a predetermined position of the side wall. An auxiliary combustion gas nozzle is installed on a side wall nearby, and a plurality of auxiliary combustion gas nozzles are installed on a side wall near the opening so that the air and the auxiliary combustion gas form a swirling flame. And an inner diameter of the waste gas inlet or the cylindrical member is gradually increased toward the combustion chamber. Burner part, Combustion chamber which is installed in the downstream of the said burner part and consists of a cylindrical member which has a 1st diameter, A combustion gas cooling unit provided at a downstream side of the combustion chamber and composed of a cylindrical member having a second diameter larger than the first diameter, The burner unit, the combustion chamber and the combustion gas cooling chamber are integrally installed, The burner unit is provided with a waste gas inlet for introducing waste gas, an air nozzle for introducing air to generate a swirling air flow, and an auxiliary combustion gas nozzle for injecting auxiliary combustion gas, The combustion gas cooling unit is provided with a liquid spray nozzle for cooling the waste gas flowing from the combustion chamber to the ceiling of the combustion gas cooling unit to spray a liquid for capturing the dust in the waste gas, and an exhaust pipe for discharging the waste gas. And a drainage pipe for draining the liquid sprayed with the liquid spray nozzle.

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